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A study on the mesh size selectivity by alternate haul method of trawl using the SELECT model (SELECT 모델을 이용한 트롤 비교 시험조업법에 의한 망목 선택성에 관한 연구)

  • Seonghun KIM;Hyungseok KIM;Sena BAEK;Jaehyung KIM;Pyungkwan KIM
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.59 no.2
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    • pp.99-109
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    • 2023
  • In this study, a comparative test operation was conducted through the alternate haul method to examine the selectivity of the four mesh sizes (60 mm, 90 mm, 110 mm, and 130 mm) of the trawl codend. The selectivity was analyzed using the SELECT model considering the fishing efficiency (split parameter) of each fishing gear in the comparative test fishing operation in the trawl and the maximum likelihood method for parameter estimation. A selectivity master curve was estimated for several mesh sizes using the extended-SELECT model. As a result of analyzing the selectivity for silver croaker based on the results of three times hauls for each experimental gear, it was found that the size of the fish caught increased as the size of the mesh size increased. When the selectivity for each mesh size analyzed by the SELECT model considering the split ratio was evaluated based on the size of the AIC value, the estimated split model was superior to the equal split model. Based on the master curve, the 50% selection length value was 2.893, which was estimated to be 136 mm based on the mesh size of 60 mm. In some selectivity models, there was a large deviance between observed and theoretical values due to the non-uniformity of the distribution of fished length classes. As a result, it is considered that appropriate sea trials and selectivity evaluation methods with high reliability should be applied to present trawl fishery resource management methods.

Composition and Abundance of Meiofaunal biofouling on the Surface of Plastic Debris Washed Ashore (해변 표착 플라스틱 쓰레기 서식 중형저서부착생물 조성과 서식밀도)

  • Eun-Ran Baek;Minju Kim;Hyeon Kim;Jung-Hoon Kang
    • Ocean and Polar Research
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    • v.45 no.3
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    • pp.125-140
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    • 2023
  • We investigated meiofaunal biofouling (40-1,000 ㎛) on stranded marine plastic debris (hereafter MPD) collected from 8 coastal areas highly affected by plastic pollution located in the southern part of Korea during June, 2021, in order to analyze the abundance and composition of MPD associated organisms. A total of eight shapes of MPD was collected and classified into four types of plastics (LDPE, PET, PP and EPS) based on Resin Identification Coding System. Meiofounal biofouling was identified into 35 taxa belonging to 11 phylum, 10 classes and 12 order, and were numerically dominated by harpacticoids (EPS: 21.6%, PP: 27.1%), nematodes (LDPE: 23.2%) and foraminiferans (PET: 29.6%). Surface area of MPD was negatively correlated with abundances of organisms on the plastic debris (r = -0.487, p < 0.05, n = 24), indicating that abundances (avg. 3,225 inds. 0.1 m-2) on the smallest area of PP debris (avg. 0.0208 m2 ) were higher than those (avg. 50 inds. 0.1 m-2) on the largest area of LDPE debris (avg. 0.4029 m-2). Whereas, there was no correlation between surface area of MPD and the number of taxa on the debris (r = 0.147, p = 0.49, n = 24). These results showed that higher abundances of meiofaunal biofouling were observed on the PP material debris than those on the other debris collected from eight hot spots of the southern coastal waters in Korea, associated with not only polymer type and surface area of the PP debris, but also possibly surface microstructure of the PP debris.

A Trend Analysis of Floral Products and Services Using Big Data of Social Networking Services

  • Park, Sin Young;Oh, Wook
    • Journal of People, Plants, and Environment
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    • v.22 no.5
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    • pp.455-466
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    • 2019
  • This study was carried out to analyze trends in floral products and services through the big data analysis of various social networking services (SNSs) and then to provide objective marketing directions for the floricultural industry. To analyze the big data of SNSs, we used four analytical methods: Cotton Trend (Social Matrix), Naver Big Data Lab, Instagram Big Data Analysis, and YouTube Big Data Analysis. The results of the big data analysis showed that SNS users paid positive attention to flower one-day classes that can satisfy their needs for direct experiences. Consumers of floral products and services had their favorite designs in mind and purchased floral products very actively. The demand for flower items such as bouquets, wreaths, flower baskets, large bouquets, orchids, flower boxes, wedding bouquets, and potted plants was very high, and cut flowers such as roses, tulips, and freesia were most popular as of June 1, 2019. By gender of consumers, females (68%) purchased more flower products through SNSs than males (32%). Consumers preferred mobile devices (90%) for online access compared to personal computers (PCs; 10%) and frequently searched flower-related words from February to May for the past three years from 2016 to 2018. In the aspect of design, they preferred natural style to formal style. In conclusion, future marketing activities in the floricultural industry need to be focused on social networks based on the results of big data analysis of popular SNSs. Florists need to provide consumers with the floricultural products and services that meet the trends and to blend them with their own sensitivity. It is also needed to select SNS media suitable for each gender and age group and to apply effective marketing methods to each target.

University Students' Life Experiences in (Non-)face-to-face Education Situations due to COVID-19 (코로나19로 인한 대학생의 (비)대면 교육 상황 속 생활경험)

  • Youngmi An;Youngran An
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.223-238
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    • 2023
  • This research presents the actual situation analysis and suggestions for the changes, experiences, and process of adaptation that college students have experienced throughout their studies and life over the past two years and more. In-depth interviews were conducted with university students, who are educational objects, and qualitative analysis methods were used to explore the overall living experiences under the pandemic situation. The interview questions were composed to cover classes, life, and emotional experiences after COVID-19, and the result of analyzing the responses boiled down to four super-categories of 'adaptation process to a new system, daily incontinence, struggle for health, and longing for connection.' This study is significant in that it analyzed the experiences and intimate changes of individual college students in unexpected and challenging situations, and urged the myriad aspects that universities, society, and the government should illuminate and respond to.

A report of 20 unrecorded bacterial species isolated from the coastal area of Korean islands in 2022

  • Hyerim Cho;Yeonjung Lim;Sumin Kim;Hyunyoung Jo;Mirae Kim;Jang-Cheon Cho
    • Journal of Species Research
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    • v.12 no.2
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    • pp.165-173
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    • 2023
  • Bacterial communities inhabiting islands play a vital role in the functioning and formation of a unique, isolated ecosystem. Nevertheless, there has been a lack of systematic research on the indigenous microbiological resources of the islands in Korea. To excavate microbial resources for further studies on the metabolism and biotechnological potential, a standard dilution plating was applied to coastal seawater samples collected from islands along the west coast of the Korean Peninsula, including Deokjeokdo, Baengnyeongdo, and Daebudo in 2022. A total of 2,007 bacterial strains were isolated from the samples as single colonies and identified using 16S rRNA gene sequence analyses. A total of 20 strains, with ≥98.7% 16S rRNA gene sequence similarity to bacterial species having validly published names but not reported in Korea, were designated as unrecorded bacterial species in Korea. The unrecorded bacterial strains were phylogenetically diverse and belonged to four phyla, five classes, 12 orders, 17 families, and 18 genera. The unreported species were assigned to Algimonas, Amylibacter, Notoacmeibacter, Roseibium, and Terasakiella of the class Alphaproteobacteria; Alteromonas, Congregibacter, Marinagarivorans, Marinicella, Oceanospirillum, Psychromonas, Thalassotalea, Umboniibacter, and Vibrio of the class Gammaproteobacteria; Lutibacter and Owenweeksia of the class Flavobacteriia; Paenibacillus of the class Bacilli; and Pelagicoccus of the class Opitutae. The taxonomic characteristics of the unreported species, including morphology, biochemistry, and phylogenetic position are provided in detail.

Optimal Design Space Exploration of Multi-core Architecture for Real-time Lane Detection Algorithm (실시간 차선인식 알고리즘을 위한 최적의 멀티코어 아키텍처 디자인 공간 탐색)

  • Jeong, Inkyu;Kim, Jongmyon
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.3
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    • pp.339-349
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    • 2017
  • This paper proposes a four-stage algorithm for detecting lanes on a driving car. In the first stage, it extracts region of interests in an image. In the second stage, it employs a median filter to remove noise. In the third stage, a binary algorithm is used to classify two classes of backgrond and foreground of an input image. Finally, an image erosion algorithm is utilized to obtain clear lanes by removing noises and edges remained after the binary process. However, the proposed lane detection algorithm requires high computational time. To address this issue, this paper presents a parallel implementation of a real-time line detection algorithm on a multi-core architecture. In addition, we implement and simulate 8 different processing element (PE) architectures to select an optimal PE architecture for the target application. Experimental results indicate that 40×40 PE architecture show the best performance, energy efficiency and area efficiency.

Floral Design Courses to Build Self-Esteem in Children Enrolled in the Community Child Care Center for Low-Income Families: Focused on the Accreditation Process of the Junior Florist Certification

  • Park, Young Hwa;Yun, Suk Young;Choi, Byung Jin;Choi, Hyun Sug
    • Journal of People, Plants, and Environment
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    • v.22 no.4
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    • pp.375-384
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    • 2019
  • The purpose of this study was to look into the influence of the junior florist training course on self-esteem of children in low-income families at the community child care center. Accordingly, the program was carried out by dividing 46 children into two groups from June 2 to August 30, 2017. The program was designed into 12 sessions of floral arrangement classes, followed by the certification test. For the program, this study set 11 flower forms focusing on line, surface, and mass arrangements as the basic forms of the western flower arrangements. For the certification test, this study had the participants take the junior florist course implemented by the Korea Ggotggozi Daegyeong Association. Seventy four percent of the total participants in this program acquired a Junior Florist Certificate. As a result, self-esteem of the experimental group significantly improved (p=.000). By items of self-esteem, the experimental group showed significant changes in social self-esteem (p=.002), familial self-esteem (p=.016), and academic self-esteem (p=.031). General self-esteem did not show a statistically significant difference, but there was an improvement by 1.9%, and this study found that there was a 5.4% change on average in social, familial, and academic self-esteem. By gender, it was found that both male (p=.003), and female participants (p=.013) showed a significant change. By grade, there were significant changes in both the lower grades (p=.014), and higher grades (p=.003).

The Effects of a Memoir Writing Program for the Elderly Using Cognitive Enhancement Techniques (기억 향상 요소를 강화한 노인 집단 자서전 쓰기 프로그램의 효과)

  • Jin, Young Sun;Kim, Young Kyoung
    • 한국노년학
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    • v.31 no.2
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    • pp.401-417
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    • 2011
  • The life review means a process of appraising life of oneself and it is essential for finding the meaning of life in old age. The memoir writing is a kind of method of life review. The memoir writing program used in this study focused especially on enhancing the cognitive skills by providing priming and retrieval support for memory performance in reminiscing past experiences. All fourteen participants were healthy and normal community dwellers and attended four-month long programof memoir writing classes which are consisted of different themes for each week. The aim of this study was to examine if the memoir writing program would render the positive effect on mental health and cognitive ability of the elderly. The results were that quality of life, life satisfaction, ego integrity of the participants showed positive change and the level of depression was significantly reduced compared to that of the control group. The findings in the present study suggest that the memoir writing can serve as one of the community initiative program to the growing population of the elderly for their emotional and cognitive challenges that they face everyday. To warrant the validity of the program, further study is needed for other sectors of elderly population, such as elderly living alone or those with both physical and/or cognitive disadvantages.

The Effects of Incised Meandering Valley and Lithological Differences on the Grain Size and Shape of Channel Bed Materials: A Case Study of the Upper and Middle Reaches of Gongneungcheon River (감입곡류 지형과 암질 차이가 하상 퇴적물 입경 및 형상에 미친 영향: 공릉천 중상류 구간을 사례로)

  • Chen, Hui;Kim, Jong Wook;Han, Min;Byun, Jongmin
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.1
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    • pp.15-26
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    • 2019
  • In this study, we investigated the grain size, lithological type, and shape of coarse bed materials in the upper and middle reaches of Gongneungcheon River. For this purpose, 11 sampling points were selected along the river. For 100 samples of the coarse bed materials at each point, three axes (long, intermediate, and short) of samples were measured, and their lithological types were also identified. By measuring grain size, the sphericity and flatness of samples were calculated. Finally, every particle was classified into four shape categories: sphere, disc, blade and rod. We found that the grain size in incised meandering reach is the largest. This is mainly due to the supply of coarse materials from steep valley sides along the meandering channel. According to the lithological analysis, all samples were identified as granite, gneiss and schist, and quartz. The proportion of granite decreased, whereas the proportion of gneiss and schist increased downstream. These patterns indicate that the bedrock distribution within the study area accounts for the downstream lithological variation of coarse bed materials. With regard to the grain shape, sphericity gradually decreased while flatness gradually increased downstream. In the case of the shape classification, unlike the general downstream pattern of grain shape, the proportion of the sphere type decreased and the proportion of the blade type increased downstream. Such a reversal change in the downstream direction turns out to be determined by the lithology (such as foliation, bedding and the pattern of weathering) of coarse bed materials.

Exploring Types of Elementary School Students' Failures in an Engineering Design Process and How Students Cope with Them (공학적 설계 과정에서 초등학생들이 마주하는 실패 경험과 이에 대한 대처 행동의 특징 탐색)

  • Sim, Ju Yeon;Park, Jisun
    • Journal of Korean Elementary Science Education
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    • v.42 no.4
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    • pp.577-590
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    • 2023
  • This study explored types of failure encountered by elementary school students during the engineering design process and how they coped with them. To achieve this goal, we developed and taught engineering design lessons on water shortages to four fourth-grade classes, observing and interviewing seven focus groups. Our analysis revealed that student failures can be categorized into two main types: those caused by cognitive factors and those influenced by environmental factors. While cognitive failures are typically within students' control, environmental factors are beyond their reach. Our findings also showed that students tended to avoid discussing the root causes of failure and instead relied on ad hoc solutions. Additionally, some students lowered their expectations for success to avoid failure. Based on our findings, we offer practical recommendations for educators to help students learn from their failures in a constructive manner.